FLUID DYNAMICS OF THE EXCRETORY FLOW OF MUCIN CONTENTS IN RAT GASTRIC GLAND PROCESSED BY HIGH PRESSURE FREEZING/FREEZE SUBSTITUTION.

高压冷冻/冷冻置换顺序后Lowicryl K4 M包埋提供了极好的超微结构，并保留了大鼠胃腺以及腔内液体内容物的抗原性。利用这一优势，我们用组织化学方法研究了大鼠胃腺腔中酶原和粘蛋白内容物的排泄流。结合KMnO_4-UA/Pb染色和Griffonia simplicifolia凝集素（GSA）-II标记的粘液颈细胞（MNC）粘蛋白，可区分腺腔中的外切的产酶内容物和MNC粘蛋白。有趣的是，在基部和颈部区域，产酶内容物显示出液滴样外观，与MNC粘蛋白形成明显的界面。在小窝区域，GSA-II标记显示了被指定为MNC粘液通道的受限路径，其流入表面粘液凝胶层。值得注意的是，酶原内容物在该区域并入MNC粘液通道。在胃小凹顶部区域，表面粘液凝胶层显示三种类型的胃粘蛋白的层状阵列。综合以上结果，我们提出了一个大鼠胃腺排泄流的模型。

The high-pressure freezing/freeze substitution sequence followed by Lowicryl K4M embedding provided an excellent ultrastructure and retention of antigenicity of rat gastric glands as well as the intraluminal fluid contents. By taking this advantage, we histochemically investigated the excretory flow of the zymogenic and mucin contents in rat gastric glandular lumen. The combination of KMnO4-UA/Pb staining for zymogenic contents and Griffonia simplicifolia agglutinin (GSA)-II labeling for mucous neck cell (MNC) mucin distinguished the exocytosed zymogenic contents from the MNC mucin in the glandular lumen. Interestingly, at the base and neck regions, the zymogenic contents showed a droplet-like appearance, forming a distinct interface with the MNC mucin. At the pit region, the GSA-II labeling demonstrated restricted paths, designated as MNC mucous channels, which flowed into the surface mucous gel layer. It is noted that the zymogenic contents merged into the MNC mucous channels at this region. At the top pit region, the surface mucous gel layer showed laminated arrays of three types of gastric mucins. Taking together, we propose a model of the excretory flow in rat gastric gland.